Viagra

An Inside Look at How Viagra Works.

Viagra is a household name. Nearly everyone knows what Viagra does. Viagra causes a man with erectile dysfunction to be able to get an erection when sexually stimulated. The question on a lot of minds is HOW does Viagra do this? How does Viagra “know” to work when a man is sexually stimulated?

The Anatomy of the Penis

Before we can understand how Viagra works, we must first understand how the penis works. In most instances, when we want to move or control a body part we think about it and it happens. This is because most body parts are moved with muscles. The penis, on the other hand, is controlled by pressurized blood. When a man is not aroused, the arteries that carry this blood to the penis are constricted. However, when a man is aroused these arteries open up and allow blood to flow into the penis, resulting in an erection. These arteries do not open properly when a man has erectile dysfunction.

How Blood Flows to the Penis

Your brain needs to be able to turn on and off the valve of blood flow to the penis. The control of blood flow is a four-step process. The first step is that the brain sends a signal down a nerve fiber, which ends in an NANC nerve cell in an artery. NANC, nonadrenergic-noncholinergic nerve cell, is able to create nitric oxide. Next, the NANC injects nitric oxide into the blood. Then the nitric oxide stimulates guanylate cyclase in nearby cells, and this enzyme starts producing a chemical called cyclic guanosine monophosphate (cGMP). The final step is that the cGMP relaxes the smooth muscles in the artery, which increases blood flow. There is one last thing that happens in this process. Another enzyme called phosphodiesterase (PDE) deactivates the cGMP, which stops the flow of blood.

How Viagra Controls Blood Flow

Viagra eliminates the PDE that is decomposing the cGMP, so cGMP builds up in the penis and has a larger effect on the artery walls. The greater the amount of cGMP the greater the blood flow, and the greater the blood flow the greater the degree of the erection. The human body has 11 types of PDE, only one of which, PDE5, is found in the penis. The makers of Viagra simply had to find a chemical that would block PDE5 only. PDE5 is an enzyme that accepts cGMP and breaks it down. Sildenafil gums up the PDE5 and disables it, allowing an erection to occur and last longer. Viagra contains sildenafil.

When a man takes Viagra, the sildenafil flows through his body and primarily affects the PDE5 enzyme in the penis. Viagra stays in the bloodstream for about 4 hours, after which it is flushed from the body via the liver and kidneys.

The Viagra Process

First a man takes Viagra. The sildenafil enters his bloodstream and flows throughout his body. The sildenafil attaches to the PDE5 enzyme and disables it. When the man becomes sexually aroused, the brain tells the NANC cells in his penis to produce nitric oxide. The nitric oxide creates cGMP and the cGMP begins to relax the penile arteries. Since Viagra has disabled the PDE5, the cGMP in the penis doesn’t break down but instead it builds up and the arteries in the penis fully dilate. The penis then fills with pressurized blood and an erection occurs.

Side Affects of Viagra

Viagra works perfectly for most men, however nearly all drugs have side affects because they are flowing throughout the entire body, not just the part that needs the drug. Viagra blocks PDE5 but it also can block PDE6 which is an enzyme that affects the cones of the retina. Because of this, Viagra can have an affect on color vision. Another side affect of Viagra affects users who take nitroglycerin for angina. Nitroglycerin works by increasing nitric oxide, which helps angina by opening the arteries that take oxygen to the heart. Taking Viagra with nitroglycerin can lead to problems. Some other side affects can range from something as simple as a headache to problems as major as a heart attack.  Another problem that could come with continued recreational use of Viagra is dependency upon it, which could lead to healthy men developing erectile dysfunction.

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Antonio LeMaire  - Search Engine Optimization expert, boasting over 7 years of algorithmic search and paid search advertising. Helping a number of Online Pharmacies like: edrugstore.md. To learn how to select a reliable online pharmacy, visit the online pharmacy knowledge base at eDrugstore.md.